Aspects of this disclosure relate generally to telecommunications, and more particularly to interference mitigation.
A wireless communication network may be deployed to provide various types of services (e.g., voice, data, multimedia services, etc.) to users within a coverage area of the network. In some implementations, one or more access points (e.g., corresponding to different cells) provide wireless connectivity for access terminals (e.g., cell phones) that are operating within the coverage of the access point(s). In some implementations, peer devices provide wireless connectively for communicating with one another.
Communication between devices in a wireless communication network may be subject to interference. For a communication between any two devices in a network, emissions of radio frequency (RF) energy by a nearby device may interfere with reception of signals at the other device. For example, a Long Term Evolution (LTE) device operating in an unlicensed RF band that is also being used by a Wi-Fi device may experience significant interference from the Wi-Fi device, and/or can cause significant interference to the Wi-Fi device.
Over-the-air interference detection is employed in some wireless communication networks in an attempt to mitigate such interference. For example, a device may periodically monitor (e.g., sniff) for energy in the RF band used by the device. Upon detection of any kind of energy, the device may back-off and refrain from accessing the RF band for a period of time.
In practice, however, there may be problems with such a back-off or “listen-before-talk” (LBT) approach, at least in its conventional implementation. For example, for an LTE system operating in an unlicensed band with a Wi-Fi co-channel scenario where it is desired to avoid interference from Wi-Fi, the detected energy in the band may not be from a Wi-Fi device, or may not be substantial. In addition, the detected energy in the band may simply be adjacent channel leakage. Consequently, an LTE device may back off transmissions in the band even when there is no Wi-Fi interference. In some wireless communication networks, inefficient utilization of available communication resources, particularly identification resources for configuration of subframes during radar detection, may lead to degradations in wireless communication. Even more, the foregoing inefficient resource utilization inhibits network devices from achieving higher wireless communication quality. Thus, improvements in interference mitigation are desired.